Frequently asked questions

All visitors to the forum "dPIPE Software" can find here answers to frequently asked questions about using dPIPE.

  1. General questions (input data, calculation parameters)

    1. 1. What does the term “reference temperature” mean in the software, and how is it utilized? [show]
    2. 2. How is the TA parameter (installation temperature) utilized in the dPIPE software? [show]
    3. 3. How can several independent piping branches be included into one calculation model? [show]
    4. 4. How to introduce in the calculation model a branch pipe? [show]
    5. 5. Unit system. Is it possible to change units for support’s reactions from “kN” to “Newton” in the output summary tables? [show]
  2. Piping elements: bends, valves, welded connections, tees

    1. 1. Should I set the middle point of bend in order to check its strength? [show]
    2. 2. How do I assign the piping valves? The data includes weight of the air-driven valve – 600 kg, length/height – 800/1800 mm, the actuator is placed at a 30 degree angle to the vertical axis. There is no data on the actuator’s weight or centers of mass. [show]
    3. 3. Which element is to be used for modeling a hinge connection between two pipes or a pipe and a construction element? [show]
    4. 4. To use command BEAM, one needs to enter certain input data, including the name of cross-section, its parameters, weight and section’s angle. How does one determine shear coefficients Sy and Sz for a beam with an arbitrary cross-section? What are the value ranges for standard cross-sections (u-beam, I-beam, box-section)? [show]
    5. 5. How the welds are considered in dPIPE? [show]
    6. 6. Standard tees. How to select “TYPE” for standard tees. Which type should be chosen to model a welded tee, a forged tee with extruded outlet? How do the tee types in the software correlate to the tee types provided by the Russian codes? [show]
    7. 7. How can one set a tee with two branches inclined on 45 deg? [show]
    8. 8. How are the unequal tee stresses determined in calculations according to RD? [show]
    9. 9. How should one set a thick-walled forged tee? [show]
  3. Expansion joints

    1. 1. How can a summary tables for expansion joints be outputted, to access data on their deformations (axial, shear, angular)? [show]
    2. 2. How to model an expansion joints in dPIPE [show]
    3. 3. How does one specify the expansion joint length in the calculation model? [show]
    4. 4. How is the expansion joint performing capacity checked judging by the analysis results? [show]
    5. 5. Should the pressure thrust force in bellows being taken into account for calculating the spring hangers design load? [show]
  4. Piping supports

    1. 1. A sliding support: which option should be selected “+/-“ or “-“? [show]
    2. 2. Do analysis results reflect the support reaction or the piping action on support? Can a horizontal load have a negative sign? [show]
    3. 3. What is a support gap clearance? In which cases should one set a support gap clearance? [show]
    4. 4. Why in the calculation results for springs there is an exclamation mark in printout, and the hangers are blinking during PIPE3DV browsing, although there is neither no exceedance of loads, or spring’s variability? [show]
  5. Fatigue strength

    1. 1. How stress analysis is realized in dPIPE? [show]
  6. Seismic and dynamic loads calculations

    1. 1. During analysis the program displays: “Warning: minimum frequency>Fmax”. What does it mean? [show]
    2. 2. How is the characteristic (vertical/horizontal) frequency chosen for an elastic model of a viscous damper? [show]
    3. 3. Does dPIPE provide an option for assessing fatigue induced by piping vibration? [show]
  7. Specification for analysis; typical errors raised during solution

    1. 1. During analysis, the following error appears: «Error: nonlinearities not converged» [show]
    2. 2. During analysis, the following error appears: «non-positive definite matrix» [show]
    3. 3. What is the difference between «OPER_A» and «OPER_B» analysis types? [show]